Impulse coupling



Jan. 2, 1940. c 5 515 2,185,818

IMPULSE COUPLING Filed Nov. 19, 1937 2 Sheets-Sheet 1 FIG. 1 x

5m: [Q3 mg INVENTOR. CURT F. Rees A TTORN E Y.

Jan. 2, c. 5515 2,185,818

IMPULSE COUPLING Filed Nov. 19, 1937 2 Sheets- Sheet 2 INVENTOR.

Cum" E R525 G ZMM. 140M A TTORNEY.

Patented Jan. 2,1940

UNITED. STATES PATENT OFFICE muss COUPLING Curt l3. Bela, Chicago, Ill.,assignor to Superior Parts Manufacturing Company, New York,, .y N. Y., acorporation of New York Application November 1.9, 1937, Serial No.115,385 ,2 Claims. (01. ruzos) This invention relates to improvements inimpulse couplings adapted for use in connection with magnetos orelectric generators supplying ignition current to internal combustionengines and the a like. I An object oi this invention is to provide acompact, positive acting impulse coupling comprised oi but few parts,the parts being so formed and related as to effect a material reductionin the to cost oi manuiacture, and to greatly enhance ability andliie oithe coupling.

Another object is to provide an impulse coupling of the type described,which is adapted to operate with equal facility and efllciency in eithera ver- 31B tical or a horizontal position, this being attained throughthe use of resilient means, such as springs, acting on pawls in a mannerto eflect a positive engagement thereof with a stationary abutment orstop member, during a stage in the impulse m operation of the coupling.

Further objects and advantages of the present invention will becomeapparent from the following detailed description "of parts andoperation,

taken in connection with the accompanying drawings in which:

Fig. 'l is an assembly elevation of a magneto organization, with aportion thereof broken away to show the impulse coupling in assembledposition; Fig. 2 is an enlarged fragmentary sectional w elevation takenalong line 2-2 injFig. 1, showing certain details oi. the couplingassembly; Fig. 3

is a iragmentarysectional elevation of a portion of the couplingmechanism, as taken along line M in "Fig. 2; Fig. 4 is a fragmentarysectional 35 elevation of the mechanism as taken along line t--$ in Fig.2; Fig. 5 is an enlarged sectional elevation of the coupling, as takenalong line 5-! in Fig. 1; Fig. 6 is a sectional elevation taken alongline 6--8 inFig. 2, showing the coupling in opera ative assembly; Fig. 7is a plan view of the driven member forming a part of the couplingmechanism; Fig. 8 is a sectional elevation of the driven member as takenalong line 5-4 in Fig. 7; Fig. 9

is a plan view of the driving member of the im- M pulse coupling; Fig.1015 a sectional elevation of the driving member, taken along lineIll-I0 in Fig. 9 and Fig. 11 is a view in perspective of a.

modified form of pawl which may be utilized in the structure of thecoupling. Y

50 Referring to the drawings by suitable numerals of reference, i5designates generally a magneto of a in part. of laminated pole shoes 21suitably which it is operatively associated (Fig. l). The

mounted upon pole pieces 22, these eiements being carried by a shaft 25journalled in bearings 26 supported within the housing 20. The magnetois suitably attached, by means of cap screws 21 and 28, to the frame itof an engine (not shown) with screw 28 is fitted through a slide orslotted portion 29 formed in the housing 20, whereby any diametricalmisalignment of the capiscrew openings in the engine frame are takencare of. The magneto shaft is arranged in substantial, axial alignmentwith the engine shaft 3 I An operative engagement of the shafts "and 3|is attained by means of an improved impulse coupling 32 later v to befully described. The coupling 32 is in operait tive association with anabutment or catch member 33 (Figs. 1, 2 and 3) which is selectivelydisposed in the housing structure 20 adjacent the coupling 32 forpurposes to be hereinafter noted. The member 33 is, by preference,comprised in :0 part 01' a protuberance or extension 3.4, formedintegrally with an annular flange portion 35 oi the tively maintained inposition by threaded engage 3o ment of the end 42 in the aperture 31 asis clearly shown in Fig. 3. It is thus seen (Fig. 2) that an abutmentmember is provided in close proximity to the periphery oi the coupling32, whereby to readily engage any part of the coupling which as might beprojected beyond the peripheral contour of the coupling.

The coupling", now to be fully described, con-'- slsts of a drivenmember 43 and a driving member 44, the former being secured, in a manner40 hereinafter to be described, to the shaft 25, and the latter being indriven engagement with the engine shaft 3!. The member 43 (Figs. '7 and8) includes a hub or sleeve 4|;'a plate element u and pawls 49. Thesleeve 41 is formed with in- 45 tegral portions I2 and 53 havingrespectively, large and small external diameters and internal tapered,and cylindrical bores. The portion 52 has a keyway 54 thereinwhichserves a purpose to be notedlater. The portion 53 is provided with so a.slot 51 to receive and lock one end 58 of a spiral spring 59 and with acollar 530 which is adjacent the portion 52 and which has a portionflattened or cut away as at 5312. The plate 48 is provided with acentral aperture 62, having a up collar Ila of the hub or sleeve 41 tobe therein, whereby the plate may be secured to the hub or sleeve 41 ina manner to be hereinafter 5 fully described. The periphery of theplateis provided with a pair of diametrically opposed ra-' in thatposition about the sleeve 41 by spinning a projecting portion II of thecollar Ila adjacent the plate in a manner to form a, shoulder 14'lapping a face of the plate and by further welding the sleeve and platetogether as at a.

Each pawl 48, hereinabove noted, is of a planar as shape and formed froma single piece of metal stamping and is provided with a coil spring 11em. 34 is urged outward beyond the peripheral engagement with theabutment It. The use of I I the requirement of a .erweight structure onthe pawl, whereby it which the pawl may be formed in a single stamp moperation. However it is to be understood that a pawl with a.counterweight portion may 75 be employed in connection with the presentpreflnttened portion, sumciently large to permit the inserted ferredconstruction of an impulse coupling. Al-- though a pair of pawls areshown in the illustration (Fig. 2), it is apparent that one pawl onlymay be used to produce the desired impulse action of the coupling. 5 Thedriving member 44 of the coupling is, for the p pose of production at alow manufacturing cost and to reduce the number of impulse couplingparts, formed of a single sheet metal stamping, which is drawn into acup-shaped elel0 ment having a "face or flat portion II and a pcripheralwall portion 8! (Figs. 9 and 10). The face portion 88 is formed with acentral aperture .2, which is of a size sumcient to fit over the portion83 of sleeve" in a manner to be hereinafter described. The peripheralwall portion II is, by preference, provided with recessed portions II,which form intermediate stepped abutment portlons 04. .Each portion 94is provided with a selectively disposed and integrally associated cam 90element 81 which serves a purpose to be herein-- after noted. A catchelement I (Fig. 5) is suitablysecured and positioned on the inner sideof the wall portion 8!. whereby to lockingly engage an end 99 of thespring I! hereinabove noted. which is disposed in the chamber formed bythe portions II and I. v A pair of diametrically op- Posed lugs I02 arepositioned on the face 88 of v the member 44 in a manner to engagecompanion slots or recesses I03 formed in the disc portion I, of themember It'll which is suitably secured to an engine shaft 3| (Fig. 1) Anoperative enilagement of the driving member with a driving means of theengine is thus'attained. The lugs are, by preference, inserted throughand welded 86 to the face portion 88. In the preferred assembly of thecoupling (Fig.

' e) the end a or the spring a is inserted, in the slot 61 .of theportion It of thesleeve 41, and the members 43 and I! are moved relativeto each other in a manner to place the spring it under an initialtension. The sleeve portion '53 of the member I; is Jcurnalled in theaperture I! of the member 41 concurrently with the positioning of theprojections it of the plate 48 in the recessed portions as of theportion as. The tension in the spring 58 should be regulated sumcientlyto maintain the projections 63 of the plate ll in contact with theabutments M. The iournalling of the sleeve 41 in the aperture 02 servesto maintain the driving member 44 in proper alignment 25., whereby tosubstantially prevent, during the 1 coupling, any irregularities ofimpulse action caused by an improperly timed release of the pawls 49,from the stop member a. The-slidable engagement of the projections Bl inthe recesses 83 serves to maintain the members I and 44 in a properlytimed relation with respect to each other, since the extent of relativeangular rotation of the member 43 with respect to the member 44, ispredetermined by the length of. the recessed por tions ll.

The coupling 32 is mounted in an operative u position on the shaft 25(Fig. 6) by a seating of the tapered portion 52 of sleeve 41. on acorrespondingtapered section I 01 formed on the shaft 25, near its endI08. A key I08, fitted in the keyway 54 secures thecoupling to the shaftand 10 serves to effect a concurrent rotation of the member 43 and theshaft 25. The members It and N are maintained in an assembled positionon the shaft and disposed laterally thereon, by means of a nut H! whichthreadedly engages the threaded 1s engagement with u portion I i! arenasof the armature shaft 2!; the nut being locked in place on the shaft asby a cotter key H4.

In the operation of the coupling the members 43 and 44 are rotatedcounterclockwise (Fig. 2) in the direction of engine rotation until oneof the pawls H, which is urged outward by the spring 11 is brought intolocking engagement with the abutment or stop 33. As the engagementoccurs the driven member 43 is precluded from further rotation but themember 44 continues to rotate relative to the member 43 which actioneffects an increase in the tension of the spring 5!. The tension in thespring continues to increase until the cam 91 engages the pawl near itsouter end 84 in a manner to urge the pawl out of looking engagementwiththe a sudden release of the pawl and member 43 is effected.

hence of the At the time of release the tension of the spring issuiiiciently great to throw the member 43 rapidly forward in thedirection of engine rotation and at a speed in excess or the speed ofthe member H. The sudden rapid movement or the member 43 thus attainedprovides the necessary sharp impulse to the rotor of the magneto wherebya spark is generated of an intensity suitable for a proper starting ofthe engine. Alter the'engine has attained a running speed, the pawls areprevented from engaging the stop 33 by the centrifugal action on thepawl portion 81, which is suflicient to overcome the action of thesprings 11 and eflects an inward movement of the pawl ends 04 to aposition within the peripheral contour of the impulse coupling. Sincethe initial tension in the spring 58 is suflicient to overcome theturning torque of the magneto armature it, the coupling will operate asa common coupling synchronously connected between the magneto and theengine organization. It is to be noted that during the stop periods orthe driven member 0, the abutments 94 formed by the opposite ends 0! therecesses 93, move with the driving member I.

toward the projections 63 formed on the plate ll of the driven member.spaced with respect to each other in a manner to permit the cam 81 torelease the pawl from engagementwith the stop 33, before the projection83 engages the abutment 94. Thus a lost-motion connection is providedwhich serves to maintam the members 43 and 44 in a properly timedrelation with respect to each other, since the extent oi relativeangular rotation or independent movement of the members is predeterminedby the spaced relation of the abutments l4 and hence by the length ofthe recesses 93.

It will be readily seen that the herein described coupling consists of aminimum of parts which are easily made .and assembled. Furthermore, theimproved coupling is neat, compact and sturdy in construction. It willbe evident that the provision oi the guiding journal fit of the drivemember H with the sleeve 1 of the driven member l3 eliminates anytendency toward eccentricity between the coupling members 3 and 41during the impulse cycles and assures concentricity of parts whichsubstantially prevents any improper or irregular releasing of the pawls.

An important feature is that the springs 11 not only act as a means ofengagement while the The abutments are abutment 13, whereby,

magneto is in a vertical position but also assure engagement when in ahorizontal position, eliminating any danger of the engine kicking orbackfiring, thereby preventing injury to the operator while cranking theengine. The impulse coupling is timed to release on dead center but ifthe coupling fails to engage or the pawl slips off of its stop beforedead center is reached, the magneto fires on full spark advance which is30 degrees beiore dead center is reached and the engine kicks or isdriven backward with the possibility oi! a broken arm for the personcranking the engine.

It will of course be understood that the present detailed description ofparts and the accompanying drawings relate only to a single preferredembodiment of the present invention and that substantial changes may bemade in the described arrangement and construction of parts withoutdeparting from the full intended scope of the invention as detlned bythe appended claims.

I claim:

1. In an impulse coupling for a magneto, a cupshaped driving member, adriven member comprised o! a slotted tubular element and a circularplate element, a locking means for said driving and driven members, astationary abutment member located adjacent said coupling, a .pair ofpawls pivoted in diametric opposition upon the circular element, eachpawl providedwith a recess, said tubular element having correspondingrecesses therein,-each in axial alignment with one of said pawlrecesses, a spring associated with each pawl, having its ends seated inthe aligned recesses in the pawl and tubular member, said springsserving to urge the corresponding pawl ends outward oi the couplingperiphery whereby, during impulse operation of the coupling, a positiveengagement of the said pawl end with the said abutment member, will beeflected for all assembly positions of the magneto.

2. In an impulse coupling tor a magneto, a cup-shaped driving member, adriven member comprised 01 a slotted tubular element and a circularplate element, a locking means for said driving and driven members, astationary abutment member located adjacent said coupling, a memberlocated inwardly of the periphery'oi said circular element and a pinpivoting the member intermediate its ends, upon the circular element,one end portion of said pivoted member constituting a pawl adapted forengagement with said abutment member, and the other end portionprojecting substantially oppositely from the pivot pin and constitutinga pawl-loading means for actuating the pawl in response to centrifugalforce imparted to the loading means during operation of the coupling, arecess in the pawl end of said pivoted member, located relativelyadjacent said pivot pin, a corresponding recess in said tubular elementin axial register with the first said recess, a spring having its endsseated in said recesses and tending to rock said pivoted member aboutits pivot pin in a direction to project the pawl end of the memberoutward oi the coupling periphery, whereby, during impulse operation ofthe coupling, a positive engagement of the pawl with the said abutmentmember will be eflected for all assembly positions 0! the magneto.

- CURT 1". RES.

